JP2015038397A - Hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water supply system which has a better heating efficiency of hot water by a heat pump compared to a conventional hot water supply system.SOLUTION: A hot water supply system 2 includes: a heat pump 50 for absorbing heat from outside air; a tank 10 for storing hot water heated by the heat pump 50; a supply passage 40 for supplying hot water in the tank 10 to a hot water usage place; and a controller 100. The controller 100 executes low-temperature hot water storing operation for operating the heat pump 50 so that temperature of the hot water after heating by the heat pump 50 becomes lower than 60°C, and in a specific case, executes high-temperature hot water storing operation for operating the heat pump 50 so that the temperature of the hot water after heating by the heat pump 50 becomes 60°C or higher.

Description

  The technology disclosed in this specification relates to a hot water supply system.

  Patent Document 1 discloses a heat pump hot water supply system having a heat pump that absorbs heat from the outside air, a tank that stores hot water heated by the heat pump, and a supply path that supplies the hot water in the tank to the hot water use location. In the heat pump hot water supply system of Patent Document 1, the heat pump is operated so that the temperature of the hot water heated by the heat pump becomes 90 ° C. As a result of the warm water stored in the tank, the heat pump is stopped when the temperature of the water introduced from the tank to the heat pump reaches a predetermined temperature.

Japanese Patent Laid-Open No. 2003-130452

  In the hot water supply system of Patent Document 1, the heat pump is operated so that the temperature of the hot water heated by the heat pump is 90 ° C., but no consideration is given to the heating efficiency at that time. However, in recent years, a hot water supply system with higher heating efficiency has been demanded as consumers' interest in energy saving has increased.

  In this specification, compared with the conventional hot water supply system, the hot water supply system with the heating efficiency of warm water by a heat pump is provided.

  As a result of intensive studies by the present inventor, when operating the heat pump of the hot water supply system, the heating capacity per unit power (COP (Coefficient Of Performance) is also called “coefficient of performance”) as the temperature of the hot water after heating is lowered. Was found to improve. When the heating capacity per unit power is improved, the heating efficiency is also improved.

  The hot water supply system disclosed in this specification has been created based on the above findings. This hot water supply system includes a heat pump that absorbs heat from the outside air, a tank that stores hot water heated by the heat pump, a supply path that supplies the hot water in the tank to a hot water use location, and a controller. The controller performs a low temperature hot water storage operation in which the heat pump is operated so that the temperature of the hot water heated by the heat pump is lower than 60 ° C., and in a specific case, the temperature of the hot water heated by the heat pump becomes 60 ° C. or higher. Execute hot water storage operation to operate the heat pump.

  In the hot water supply system, the controller performs a low temperature hot water storage operation in which the heat pump is operated such that the temperature of the hot water heated by the heat pump is lower than 60 ° C. Compared to the conventional hot water supply system that operates the heat pump so that the temperature of the hot water after heating is 90 ° C., the above hot water supply system that executes the above low temperature hot water storage operation has a high heating capacity per unit power and heating efficiency Also good.

  In the above hot water supply system, the controller performs a high temperature hot water storage operation in which the heat pump is operated so that the temperature of the hot water heated by the heat pump becomes 60 ° C. or higher in a specific case. As a result of studies by the present inventors, it has been found that by setting the temperature of hot water to 60 ° C. or higher, fungi (such as Legionella) that may be contained in the hot water can be sterilized. According to the configuration of the feature 1, the temperature of the hot water in the tank can be set to 60 ° C. or higher by performing the high temperature hot water storage operation. Thereby, it is possible to sterilize fungi that may be contained in the hot water and appropriately prevent the hot water having the possibility of bacterial growth from being supplied to the hot water use location.

The figure which shows typically the structure of the hot water supply system 2 which concerns on 1st Example. The flowchart which shows the thermal storage driving | running which the hot water supply system 2 of 1st Example performs. The flowchart which shows the thermal storage driving | running which the hot water supply system 2 of 2nd Example performs. The figure which shows typically the structure of the hot water supply system 102 which concerns on 3rd Example.

  The main features of the embodiments described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

(Characteristic 1) It is preferable that a specific case is a case where a specific period passes after performing a high temperature hot water storage driving | operation last time.

  According to this configuration, the high temperature hot water storage operation can be executed every specific period. Therefore, according to this configuration, by setting the specific period to an appropriate period shorter than the propagation period of the fungi, the fungi that may be contained in the hot water can be appropriately sterilized.

(Characteristic 2) Even in a specific case, the controller performs the low temperature hot water storage operation without executing the high temperature hot water storage operation when the amount of hot water supplied from the tank within a unit period is equal to or greater than a specific threshold value. It is preferable to do.

  For example, when the amount of hot water supplied from the tank in the unit period is larger than the tank capacity value, the hot water in the tank is replaced within the unit period. Therefore, even if the specific period has elapsed since the previous high temperature hot water storage operation was performed, if the hot water in the tank was changed within a period shorter than the fungus breeding period, it is necessary to perform the high temperature hot water storage operation. There is no. When using the above configuration, the unit period is set to an appropriate period shorter than the fungus breeding period, and the specific threshold value is set to an appropriate value at which the hot water in the tank is replaced. Accordingly, fungi that may be contained in the hot water can be appropriately sterilized.

(Characteristic 3) In a specific case, it is preferable that the amount of hot water supplied from the tank in a unit period is smaller than a specific threshold value.

  According to this configuration, the high temperature hot water storage operation can be executed according to the amount of hot water supplied from the tank within the unit period. As described above, when the amount of hot water supplied from the tank in the unit period is larger than the tank capacity value, the hot water in the tank is replaced within the unit period. If the hot water in the tank is changed within a period shorter than the breeding period of the fungi, it is not necessary to perform a high temperature hot water storage operation. Therefore, in the case of the above configuration, the unit period is set to an appropriate period shorter than the fungus breeding period, and the specific threshold value is set to an appropriate value at which the hot water in the tank is replaced. According to the usage situation, fungi that may be contained in warm water can be sterilized appropriately.

(Characteristic 4) It is preferable that the warm water stored in a tank has the 1st layer whose average temperature of warm water is 60 degreeC or more, and the 2nd layer whose average temperature of warm water is lower than 60 degreeC. The supply path preferably includes a first supply path that supplies the hot water in the first layer to the hot water use location and a second supply path that supplies the hot water in the second layer to the hot water use location.

  According to this structure, warm water can be appropriately supplied according to the temperature of warm water required in a warm water utilization location.

(First embodiment)
As shown in FIG. 1, a hot water supply system 2 according to the present embodiment includes a tank 10, a tank water circulation path 20, a tap water introduction path 30, a supply path 40, a heat pump 50, a burner heating device 60, and a controller. 100.

  The heat pump 50 is a heat source that absorbs heat from the outside air and heats the water in the tank water circulation path 20. Although not shown, the heat pump 50 includes a heat medium circulation path that circulates a heat medium (alternative chlorofluorocarbon, such as R410A), an evaporator that exchanges heat between the outside air and the heat medium, and a high temperature by compressing the heat medium. A compressor for increasing the pressure, a heat exchanger for exchanging heat between the water in the tank water circulation path 20 and the high-temperature and high-pressure heat medium, and reducing the heat medium after the heat exchange to low-temperature and low-pressure An expansion valve.

  The tank 10 stores hot water heated by the heat pump 50. The tank 10 is a hermetically sealed type, and the outside is covered with a heat insulating material. Water is stored in the tank 10 until it is full. In this embodiment, the capacity of the tank 10 is 100L. The thermistors 12, 14, 16, and 18 are attached to the tank 10 at predetermined intervals in the height direction of the tank 10. Each thermistor 12, 14, 16, 18 measures the temperature of water at its mounting position. For example, each of the thermistors 12, 14, 16, and 18 measures the temperature of water at positions 6L, 12L, 30L, and 50L from the top of the tank 10, respectively.

  The tank water circulation path 20 has an upstream end connected to the lower part of the tank 10 and a downstream end connected to the upper part of the tank 10. A circulation pump 22 is interposed in the tank water circulation path 20. The circulation pump 22 sends the water in the tank water circulation path 20 from the upstream side to the downstream side. In addition, the tank water circulation path 20 passes through a heat exchanger (not shown) of the heat pump 50. Therefore, when the heat pump 50 is operated, the water in the tank water circulation path 20 is heated by the heat exchanger of the heat pump 50. Therefore, when the circulation pump 22 and the heat pump 50 are operated, the water in the lower part of the tank 10 is heated by the heat pump 50, and the heated water is returned to the upper part of the tank 10. That is, the tank water circulation path 20 is a water path for storing heat in the tank 10. A thermistor 24 is interposed on the upstream side of the heat pump 50 in the tank water circulation path 20. The thermistor 24 is derived from the lower part of the tank 10 and measures the temperature of water before passing through the heat pump 50.

  The tap water introduction path 30 has an upstream end connected to a tap water supply source 31. A thermistor 32 is interposed in the tap water introduction path 30. The thermistor 32 measures the temperature of tap water. The downstream side of the tap water introduction path 30 branches into a first introduction path 30a and a second introduction path 30b. The downstream end of the first introduction path 30 a is connected to the lower part of the tank 10. The downstream end of the second introduction path 30b is connected to a supply path 40 described later. A mixing valve 42 is provided at a connection portion between the downstream end of the second introduction path 30 b and the supply path 40. The mixing valve 42 adjusts the amount by which the water in the second introduction path 30 b is mixed with the hot water flowing in the supply path 40.

  The upstream end of the supply path 40 is connected to the upper part of the tank 10. As described above, in the middle of the supply path 40, the second introduction path 30b of the tap water introduction path 30 is connected, and the mixing valve 42 is provided at the connection portion. A burner heating device 60 is interposed in the supply passage 40 on the downstream side of the connection portion with the second introduction passage 30b. A thermistor 44 is interposed in the supply path 40 on the downstream side of the burner heating device 60. The thermistor 44 measures the temperature of the supplied hot water. The burner heating device 60 heats the water in the supply path 40 so that the temperature of the hot water measured by the thermistor 44 matches the hot water supply set temperature. The downstream end of the supply path 40 is connected to a hot water use location (for example, a kitchen, a bathtub, etc.).

  The controller 100 is electrically connected to each component and controls the operation of each component. Although not shown in FIG. 1, the controller 100 is connected to a remote controller having an operation unit that allows a user to input various instructions and a display unit that can display various information.

  Next, the operation of the hot water supply system 2 of the present embodiment will be described. The hot water supply system 2 can execute a heat storage operation and a hot water supply operation. Hereinafter, each operation will be described.

(Heat storage operation)
The heat storage operation is an operation in which water in the tank 10 is heated by heat generated by the heat pump 50. The heat storage operation may be called a hot water storage operation. When the operation of the hot water supply system 2 is started, the controller 100 starts the heat storage operation shown in FIG. When the heat storage operation is started, first, in S10, the controller 100 determines whether or not the selected hot water storage mode is the low temperature hot water storage mode. The user of the hot water supply system 2 of the present embodiment can select one of the two hot water storage modes of “high temperature hot water storage mode” and “low temperature hot water storage mode” by operating the operation unit of the remote controller. However, when the user does not select the hot water storage mode in advance (for example, immediately after turning on the power), the low temperature hot water storage mode is automatically selected. When the low temperature hot water storage mode is selected, the controller 100 determines YES in S10, and proceeds to S12. On the other hand, when the high temperature hot water storage mode is selected, the controller 100 determines NO in S10 and proceeds to S16.

  In S12, the controller 100 determines whether or not 72 hours have elapsed since the previous execution of the high temperature hot water storage operation. As will be described in detail later, in the hot water storage operation, the heat pump 50 and the circulation pump 22 are operated so that the temperature Tb of hot water heated by the heat pump 50 (hereinafter referred to as “exit temperature Tb”) is 60 ° C. Driving. If 72 hours or more have elapsed since the previous execution of the high temperature hot water storage operation at the time of S12, the controller 100 determines YES in S12 and proceeds to S16. On the other hand, when 72 hours have not elapsed since the previous execution of the high-temperature hot water storage operation at the time of S12, the controller 100 determines NO in S12 and proceeds to S14.

  In S14, the controller 100 sets the outlet temperature Tb to a temperature (Ts + 5 ° C.) that is 5 ° C. higher than the hot water supply set temperature Ts. The hot water supply set temperature Ts is a set temperature of hot water supplied to the hot water use location. A user of the hot water supply system 2 can set the hot water supply set temperature Ts by operating the operation unit of the remote controller. In the present embodiment, the hot water supply set temperature Ts can be set between 35 ° C. and 45 ° C. When S14 ends, the process proceeds to S18.

  On the other hand, in S16, the controller 100 sets the outlet temperature Tb to 60 ° C. When S16 ends, the process proceeds to S18.

  In S18, the controller 100 determines whether or not the temperature detected by the thermistor 12 (that is, the temperature of water stored in the upper part of the tank 10) is equal to or lower than the hot water supply set temperature Ts. When the temperature detected by the thermistor 12 is equal to or lower than the hot water supply set temperature Ts, the controller 100 determines YES in S18 and proceeds to S20. If YES in S18, this means that hot water at the hot water supply set temperature Ts is not stored in the tank 10 at this time. On the other hand, when the temperature detected by the thermistor 12 is higher than the hot water supply set temperature Ts, the controller 100 determines NO in S18, skips the processes of S20, S22, and S24 and proceeds to S26. In the case of NO in S18, this means that hot water having a temperature higher than the hot water supply set temperature Ts is stored in the tank 10 at this time.

  In S <b> 20, the controller 100 operates the heat pump 50 and the circulation pump 22. At this time, the controller 100 operates the heat pump 50 so that the outlet temperature Tb becomes the temperature (Ts + 5 ° C. or 60 ° C.) set in S14 or S16. More specifically, the controller 100 adjusts the rotation speed of the motor of the compressor so that the outlet temperature Tb of the heat pump 50 becomes the temperature set in S14 or S16.

  When the circulation pump 22 is activated, the water in the tank 10 circulates in the tank water circulation path 20. That is, the water existing in the lower part of the tank 10 is introduced into the tank water circulation path 20 and is set in S14 or S16 depending on the heat of the heat medium when the introduced water passes through the heat exchanger in the heat pump 50. It is heated to the outlet temperature Tb. The water heated to the outlet temperature Tb is returned to the upper part of the tank 10. Thereby, the water of the outlet temperature Tb is stored in the tank 10. As a result, a high temperature water layer is formed in the upper part of the tank 10 and a low temperature water layer is formed in the lower part.

  In S20, the operation when the heat pump 50 and the circulation pump 22 are operated so that the outlet temperature Tb becomes the temperature (Ts + 5 ° C.) set in S14 is hereinafter referred to as “low temperature hot water storage operation”. On the other hand, in S20, the operation when the heat pump 50 and the circulation pump 22 are operated so that the outlet temperature Tb becomes the temperature (60 ° C.) set in S16 is hereinafter referred to as “high temperature hot water storage operation”. When the heat pump 50 and the circulation pump 22 are operated in S20, the process proceeds to S22.

  In S22, it is monitored whether the temperature detected by the thermistor 24 (that is, the temperature of water derived from the lower part of the tank 10 and supplied to the heat pump 50) is equal to or higher than the outlet temperature Tb set in S14 or S16. By operating the heat pump 50 and the circulation pump 22 in S20 and continuously performing the low temperature hot water storage operation or the high temperature hot water storage operation, the hot water of the outlet temperature Tb is continuously stored in the upper part of the tank 10. When the hot water having the outlet temperature Tb is stored up to the lower part of the tank 10 (that is, the tank 10 is filled with the hot water having the outlet temperature Tb), the hot water having the outlet temperature Tb is led from the lower part of the tank 10 to the tank water circulation path 20. In this case, the controller 100 determines YES in S22, and proceeds to S24.

  In S24, the controller 100 stops the heat pump 50 and the circulation pump 22. Thereby, the low temperature hot water storage operation or the high temperature hot water storage operation ends. When S24 ends, the process proceeds to S26.

  In S26, the controller 100 determines whether or not the outlet temperature Tb set in S14 or S16 is equal to or higher than the hot water supply set temperature Ts. The controller 100 determines YES in S26 unless there is a circumstance such as changing the hot water supply set temperature Ts by operating the operation unit of the remote controller. In the case of YES in S26, the controller 100 returns to the first starting step and executes the process from S10 again.

  On the other hand, when the user changes the hot water supply set temperature Ts by operating the operation unit of the remote controller, and the hot water set temperature Ts after the change becomes higher than the outlet temperature Tb (Tb <Ts), the controller 100 It is determined NO in S26. In the case of NO in S26, the controller 100 returns to S14, resets the outlet temperature Tb, and re-executes the processing after S18.

  As described above, the controller 100 repeatedly executes the heat storage operation of FIG. 2 until the operation of the hot water supply system 2 is completed.

(Hot water operation)
The hot water supply operation is an operation in which the water in the tank 10 is supplied to the hot water use location. The hot water supply operation can also be executed during the above heat storage operation. When the hot water tap at the location where the hot water is used is opened, tap water flows into the lower portion of the tank 10 from the tap water introduction path 30 (first introduction path 30a) due to the water pressure from the tap water supply source 31. At the same time, the hot water in the upper part of the tank 10 is supplied to the hot water use location via the supply path 40.

  When the temperature of the water supplied from the tank 10 to the supply path 40 (that is, the measured temperature of the thermistor 12) is higher than the hot water supply set temperature Ts, the controller 100 opens the mixing valve 42 from the second introduction path 30b. Tap water is introduced into the supply path 40. In this case, the water supplied from the tank 10 and the tap water supplied from the second introduction path 30 b are mixed in the supply path 40. The controller 100 adjusts the opening degree of the mixing valve 42 so that the temperature of the water supplied to the hot water use location matches the hot water supply set temperature Ts. On the other hand, the controller 100 operates the burner heating device 60 when the temperature of the water supplied from the tank 10 to the supply path 40 is lower than the hot water supply set temperature Ts. In this case, the water passing through the supply path 40 is heated by the burner heating device 60. The controller 100 controls the output of the burner heating device 60 so that the temperature of the water supplied to the hot water use location matches the hot water supply set temperature Ts.

  The configuration and operation content of the hot water supply system 2 according to the present embodiment have been described above. In the present embodiment, when the low temperature hot water storage mode is selected (YES in S10 of FIG. 2), the controller 100 operates the heat pump 50 and the circulation pump 22 so that the outlet temperature Tb becomes the hot water supply set temperature Ts + 5 ° C. A low temperature hot water storage operation is executed (S14, S20). Therefore, the hot water supply system 2 when the low temperature hot water storage mode is selected has a higher heating capacity (COP) per unit power than the conventional hot water supply system that operates the heat pump so that the outlet temperature becomes 90 ° C. Heating efficiency is also good.

  In this embodiment, the outlet temperature Tb is set to 60 ° C. even when the high temperature hot water storage mode is selected (NO in S10 of FIG. 2). Therefore, in this embodiment, even when the high temperature hot water storage mode is selected, the heating capacity per unit power is higher than that of the conventional hot water supply system that operates the heat pump so that the outlet temperature becomes 90 ° C. Also, heating efficiency is good.

  In this embodiment, the hot water in the tank 10 is heated to 60 ° C. by operating the heat pump 50 so that the outlet temperature Tb becomes 60 ° C. and performing the high-temperature hot water storage operation. By heating the hot water in the tank 10 to 60 ° C., fungi (such as Legionella) that may be contained in the hot water in the tank 10 can be sterilized.

  According to the study of the present inventor, if the hot water in the tank 10 is kept at a temperature lower than 60 ° C. continuously for at least 96 hours (4 days), the possibility that the fungi start to breed in the tank 10 increases. It has been found. As described above, in this embodiment, even when the low temperature hot water storage mode is selected (YES in S10), when 72 hours have passed since the previous execution of the high temperature hot water storage operation (YES in S12). The controller 100 automatically sets the outlet temperature Tb to 60 ° C. (S16), and then executes the high temperature hot water storage operation (S20). Therefore, the inside of the tank 10 can be appropriately sterilized before the fungi begin to propagate in the tank 10.

(Second embodiment)
The second embodiment will be described focusing on the differences from the first embodiment. The basic configuration of the hot water supply system 2 of this embodiment is also the same as that of the hot water supply system 2 of the first embodiment (see FIG. 1). In the present embodiment, a part of the content of the heat storage operation is different from the first embodiment. With reference to FIG. 3, the thermal storage operation which the hot water supply system 2 of a present Example performs is demonstrated.

  When the operation of the hot water supply system 2 is started, the controller 100 starts the heat storage operation shown in FIG. When the heat storage operation is started, first, in S40, the controller 100 determines whether or not the selected hot water storage mode is the low temperature hot water storage mode. Since the process of S40 is the same as the process of S10 of FIG. 2, detailed description is omitted. If YES in S40, the process proceeds to S41. On the other hand, if NO in S40, the process proceeds to S46.

  In S42, the controller 100 determines whether 72 hours have passed since the previous execution of the high-temperature hot water storage operation. The process of S42 is the same as the process of S12 of FIG. If YES in S42, the process proceeds to S43. On the other hand, if NO in S42, the process proceeds to S44.

  In S43, the controller 100 determines whether or not the amount of tapping water within 72 hours is 100L or more. If 100 L or more of hot water is supplied from the tank 10 to the hot water use location within the past 72 hours with the time point of S43 as a reference, the controller 100 determines YES in S43 and proceeds to S44. On the other hand, if 100 L or more of hot water has not been supplied from the tank 10 to the hot water use location within the past 72 hours, the controller 100 determines NO in S43 and proceeds to S46.

  In S44, the controller 100 sets the outlet temperature Tb to a temperature (Ts + 5 ° C.) that is 5 ° C. higher than the hot water supply set temperature Ts. On the other hand, in S46, the controller 100 sets the outlet temperature Tb to 60 ° C. Since each process of S44 and S46 is the same as each process of S14 and S16 of FIG. 2, detailed description is abbreviate | omitted.

  The subsequent processes of S48, S50, S52, S54, and S56 are also the same as the processes of S18, S20, S22, S24, and S26 of FIG.

  As described above, also in this embodiment, the controller 100 repeatedly executes the heat storage operation of FIG. 3 until the operation of the hot water supply system 2 is completed.

  The hot water supply system 2 according to the present embodiment has been described above. In this embodiment, when the low temperature hot water storage mode is selected (YES in S40 of FIG. 3), the controller 100 is in a case where 72 hours have elapsed since the previous execution of the high temperature hot water storage operation (YES in S42). However, when the amount of discharged hot water within 72 hours is 100 L or more (YES in S43), the high temperature hot water storage operation is not performed thereafter, and the low temperature hot water storage operation is performed (S44, S50). If the amount of tapping water in the past 72 hours is 100 L or more, it means that all the water in the tank 10 has been replaced within the past 72 hours. As described above, the fungus breeding period is at least 96 hours, so even if 72 hours or more have elapsed since the previous high-temperature hot water storage operation, the water in the tank 10 is changed within 72 hours. Is less likely to propagate fungi in the tank 10. In this case, the heating efficiency can be kept high by not performing the high temperature hot water storage operation.

  In this embodiment, when the low temperature hot water storage mode is selected (YES in S40 of FIG. 3), 72 hours have passed since the previous execution of the high temperature hot water storage operation (YES in S42), and 72 Only when the amount of discharged hot water within the time is less than 100 L (NO in S43), the high temperature hot water storage operation is executed instead of the low temperature hot water storage operation (S46, S50). That is, when the low temperature hot water storage mode is selected, the high temperature hot water storage operation can be performed only in a situation where the high temperature hot water storage operation needs to be performed to perform sterilization. The fungi that may be contained in the hot water in the tank 10 can be appropriately sterilized in accordance with the usage state of the hot water stored in the tank 10.

(Third embodiment)
The third embodiment will be described focusing on differences from the first embodiment. As shown in FIG. 4, the hot water supply system 102 of the present embodiment also includes a tank 10, a tank water circulation path 20, a tap water introduction path 30, a supply path 40, a heat pump 50, a burner heating device 60, and a controller 100. Is common to the first embodiment. The hot water supply system 102 according to the present embodiment is provided with a branch passage 120 in the middle of the tank water circulation passage 20 and a lead-out passage 130 that connects the tank 10 and the second introduction passage 30b. It differs from the hot water supply system 2 (refer FIG. 1) of 1 Example.

  The upstream end of the branch path 120 is connected to the downstream side of the heat pump 50 in the tank water circulation path 20. The downstream end of the branch path 120 is connected to the vicinity of the center of the tank 10 in the height direction. A switching valve 122 is provided at a connection portion between the upstream end of the branch path 120 and the tank water circulation path 20. In the switching valve 122, the hot water that has passed through the heat pump 50 passes through the tank water circulation path 20 as it is and is supplied to the upper portion of the tank 10, and the hot water that has passed through the heat pump 50 passes through the branch path 120 and the height of the tank 10 The state supplied to the central portion in the direction can be switched.

  In the present embodiment, when the controller 100 executes the low temperature hot water storage operation, the controller 100 puts the switching valve 122 in a state where the hot water that has passed through the heat pump 50 passes through the branch path 120 and is supplied to the center in the height direction of the tank 10. Switch. Accordingly, the hot water heated to the outlet temperature Tb (= hot water supply set temperature Ts + 5 ° C.) by the heat pump 50 is supplied to the vicinity of the central portion in the height direction of the tank 10. On the other hand, when executing the high temperature hot water storage operation, the controller 100 switches the switching valve 122 to a state where the hot water that has passed through the heat pump 50 passes through the tank water circulation path 20 and is supplied to the upper portion of the tank 10. Thereby, the hot water heated to the outlet temperature Tb (= 60 ° C.) by the heat pump 50 is supplied to the upper portion of the tank 10.

  As a result, the warm water stored in the tank 10 in this embodiment includes the high temperature layer 112 having an average temperature of 60 ° C., the intermediate temperature layer 114 having an average temperature of the warm water lower than that of the high temperature layer 112, and the average temperature of the warm water being an intermediate temperature. And a lower temperature layer 116 lower than the layer 114. The average temperature of the hot water in the middle temperature layer 114 is the hot water supply set temperature Ts + 5 ° C. The intermediate temperature layer 114 is formed below the high temperature layer 112. The low temperature layer 116 is formed below the intermediate temperature layer 114.

  The lead-out path 130 connects the vicinity of the center in the height direction of the tank 10 and the second introduction path 30b. A regulating valve 146 is provided at a connection portion between the lead-out path 130 and the second introduction path 30b. The adjustment valve 146 changes the opening degree to thereby change the flow rate of hot water in the tank 10 (hot water in the intermediate temperature layer 114) supplied from the outlet passage 130 and tap water supplied from the second introduction passage 30b. The rate of flow can be changed.

  In the present embodiment, the regulating valve 142 is also provided at the connection portion between the supply path 40 and the downstream end of the second introduction path 30b. The regulating valve 142 changes the opening degree thereof, whereby the flow rate of the hot water (hot water in the high temperature layer 112) supplied from the upper part of the tank 10 to the supply path 40 and the water (tap water) supplied from the second introduction path 30b. It is possible to change the flow rate ratio of at least one of water and hot water supplied from the outlet 130.

  During the hot water supply operation, the controller 100 adjusts the opening degree of the adjustment valve 146 and the opening degree of the adjustment valve 142 so that the temperature of the water supplied to the hot water use location matches the hot water supply set temperature. Also in this embodiment, when the temperature of the water supplied from the tank 10 to the supply path 40 is lower than the hot water supply set temperature, the controller 100 determines that the temperature of the water supplied to the hot water use location matches the hot water supply set temperature. Thus, the output is controlled so that the burner heating device 60 is operated.

  The hot water supply system 102 according to the present embodiment has been described above. As described above, the warm water stored in the tank 10 in this embodiment has the high temperature layer 112 having an average temperature of 60 ° C., the middle temperature layer 114 having an average temperature of the warm water lower than that of the high temperature layer 112, and the average temperature of the warm water. A low temperature layer 116 lower than the intermediate temperature layer 114. Further, in this embodiment, by adjusting the opening degree of the regulating valve 146 and the opening degree of the regulating valve 142, both hot water in the high temperature layer 112 and hot water in the intermediate temperature layer 114 are supplied to the hot water use location. be able to. Therefore, in a present Example, warm water can be appropriately supplied according to the temperature of warm water required in a warm water utilization location.

  The correspondence relationship between the present embodiment and the claims will be described. A portion of the supply path 40 between the tank 10 and the adjustment valve 142 is an example of a “first supply path”. A portion between the adjustment valve 146 and the adjustment valve 142 in the lead-out path 130 and the second introduction path 30b is an example of the “second supply path”. In the supply path 40, the downstream side of the adjustment valve 142 is an example of the “supply path”. The high temperature layer 112 and the intermediate temperature layer 114 are examples of the “first layer” and the “second layer”, respectively.

  Each embodiment has been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

(Modification 1) In each of the above embodiments, when performing the low temperature hot water storage operation, the heat pump 50 and the circulation pump 22 are operated with the outlet temperature Tb set to the hot water supply set temperature Ts + 5 ° C. Moreover, when performing a high temperature hot water storage operation, the outlet temperature Tb is set to 60 ° C., and the heat pump 50 and the circulation pump 22 are operated. The outlet temperature Tb when the low temperature hot water storage operation is performed and the outlet temperature Tb when the high temperature hot water storage operation is performed are not limited to the above-described temperatures, and may be arbitrary. For example, the outlet temperature Tb when performing the low temperature hot water storage operation may be set to 50 ° C., and the outlet temperature Tb when performing the high temperature hot water storage operation may be set to 90 ° C.

(Modification 2) In the first embodiment, even when the low temperature hot water storage mode is selected (YES in S10), 72 hours have passed since the previous execution of the high temperature hot water storage operation (YES in S12). The controller 100 automatically sets the outlet temperature Tb to 60 ° C. (S16), and then executes the high-temperature hot water storage operation (S20). Further, in the second embodiment, when the low temperature hot water storage mode is selected (YES in S40), even if 72 hours have elapsed since the previous execution of the high temperature hot water storage operation (YES in S42), 72 If the amount of hot water discharged within the time is 100L or more (YES in S43), then the low temperature hot water storage operation is performed without performing the high temperature hot water storage operation (S44, S50). Each period used as the reference | standard of switching of each said driving | operation content is not restricted to 72 hours, It can be set as arbitrary periods.

(Modification 3) In the second embodiment, when the low temperature hot water storage mode is selected (YES in S40 of FIG. 3), the controller 100 has passed 72 hours since the previous execution of the high temperature hot water storage operation ( Only when the amount of hot water discharged within 72 hours is less than 100 L (NO in S43) (NO in S43), the high temperature hot water storage operation is executed instead of the low temperature hot water storage operation (S46, S50). Instead, in the second embodiment, the process of S42 may be omitted. That is, when the low temperature hot water storage mode is selected (YES in S40 of FIG. 3), the amount of discharged hot water within 72 hours is more than 100L regardless of whether or not 72 hours have elapsed since the previous execution of the high temperature hot water storage operation. When the number is low, the high temperature hot water storage operation may be executed instead of the low temperature hot water storage operation. In this case, the controller 100 may determine whether or not the amount of discharged hot water within 72 hours is less than 100 L only once every predetermined time (for example, 2:00 am) every day.

(Modification 4) In each of the embodiments described above, the controller 100 detects that the temperature detected by the thermistor 12 (that is, the temperature of water stored in the upper portion of the tank 10) is equal to or lower than the hot water supply set temperature Ts (in FIG. 2). The heat pump 50 and the circulation pump 22 are operated at S18 (YES at S18 and YES at S48 in FIG. 3). The position and detected temperature of the thermistor serving as a reference for operating the heat pump 50 and the circulation pump 22 are not limited to the above example, and may be arbitrary.

(Modification 5) In each said Example, the hot water supply system 2 (102) is provided with the burner heating apparatus 60 (refer FIG. 1, FIG. 4). Instead, the hot water supply system 2 (102) may omit the burner heating device 60. When the burner heating device 60 is omitted, if NO is determined in S26 of FIG. 2 (S56 of FIG. 3) (Tb <Ts), the controller 100 returns to S14 of FIG. 2 (S44 of FIG. 3), An error message indicating that hot water at the hot water supply set temperature Ts cannot be immediately supplied may be displayed on the display unit of the remote controller.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: Hot water supply system 10: Tanks 12, 14, 16, 18: Thermistor 20: Tank water circulation path 22: Circulation pump 24: Thermistor 30: Tap water introduction path 30a: First introduction path 30b: Second introduction path 31: Tap water Supply source 32: Thermistor 40: Supply path 42: Mixing valve 44: Thermistor 50: Heat pump 60: Burner heating device 100: Controller 102: Hot water supply system 112: High temperature layer 114: Medium temperature layer 116: High temperature layer 120: Branch 122: Switching Valve 130: Lead-out path 142: Adjustment valve 146: Adjustment valve

The hot water supply system disclosed in this specification has been created based on the above findings. This hot water supply system includes a heat pump that absorbs heat from the outside air, a tank that stores hot water heated by the heat pump, a supply path that supplies the hot water in the tank to a hot water use location, and a controller. The controller performs the low-temperature hot water storage operation for operating the heat pump as hot water temperature after the heating by the heat pump is lower than 60 ° C.. In the low temperature hot water storage operation, the controller operates the heat pump so that the temperature of the hot water heated by the heat pump is higher than the preset hot water supply temperature by a specific temperature. In a specific case , the controller performs a high-temperature hot water storage operation in which the heat pump is operated so that the temperature of the hot water heated by the heat pump becomes 60 ° C. or higher.

(Characteristic 4) It is preferable that the warm water stored in a tank has the 1st layer whose average temperature of warm water is 60 degreeC or more, and the 2nd layer whose average temperature of warm water is lower than 60 degreeC. It is preferable that the hot water supply system further includes a circulation path that circulates water between the tank and the heat pump and supplies hot water after being heated by the heat pump to the first layer. It is preferable that the circulation path includes a branch path that supplies hot water after being heated by the heat pump to the second layer. The supply path preferably includes a first supply path that supplies the hot water in the first layer to the hot water use location and a second supply path that supplies the hot water in the second layer to the hot water use location.

Claims (5)

A hot water system,
A heat pump that absorbs heat from the outside air,
A tank for storing hot water heated by a heat pump;
A supply path for supplying hot water in the tank to the hot water use location;
A controller, and
The controller
Execute a low temperature hot water storage operation to operate the heat pump so that the temperature of the hot water heated by the heat pump is lower than 60 ° C,
In a specific case, a high temperature hot water storage operation is performed in which the heat pump is operated so that the temperature of the hot water heated by the heat pump is 60 ° C. or higher.
Hot water system. A specific case is when a specific period of time has elapsed since the previous high temperature hot water storage operation was performed.
The hot water supply system according to claim 1. Even if the controller is a specific case, if the amount of hot water supplied from the tank within the unit period is equal to or greater than a specific threshold value, the controller performs the low temperature hot water storage operation without performing the high temperature hot water storage operation.
The hot water supply system according to claim 2. The specific case is when the amount of hot water supplied from the tank within the unit period is less than a specific threshold.
The hot water supply system according to claim 1. The warm water stored in the tank has a first layer with an average temperature of 60 ° C. or higher and a second layer with an average temperature of warm water lower than 60 ° C.,
The supply path includes a first supply path that supplies the hot water in the first layer to the hot water use location, and a second supply path that supplies the hot water in the second layer to the hot water use location,
The hot water supply system according to any one of claims 1 to 4.

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